Sharad Yadav makes this claim in yesterday's The Hindu. I have heard this before from some IAS aspirants that this sort of thing goes on and they are advised to act "upper caste" (whatever thats supposed to mean) in the interview process. I have usually dismissed this to be a case of sour grapes thing. I am trying to find out the exact details of the case here. Will post the details when (if) i find them.